The Performance Research Of Three Kinds Of Transmission Mode In LTE

Since the increasing requirements of people, such as the capacity and coverage of network and the rate of data transmission, the mobile communication technology has generated a high-speed development in recent years. The operation of deploying3G mobile network has met the requirements of people with a high data transmitting rate in a certain extent at the beginning of this century. However, with the introduction of the mobile Internet, the current network has been unable to meet the customer’s requirements based on the higher and higher developing network-based applications of bandwidth and high transmitting rates. Resulting from that the technology of OFDM and Multi-antenna has been introduced into the Long Term Evolution (LTE); it is achievement that the3GPP made a high rate of bandwidth mobile network.As the multi-antenna technology has been introduced into the LTE, the adaptability of communication system has been enhanced in different scenarios. It also increases the complexity of system implementation at the same time. Like the adaptive technology of multi-antenna, the inner&inter transmission mode switching technology can improve not only the adaptation in different scenarios in baseband, but also increases the complexity of system implementation. The strategy of inner&inter transmission mode switching has a deep influence in performance of the communication system. And then,the choice of the transmission mode switching strategy in traditional way is rely on simulation.The simulation based on the scenarios simplified by target in simulator can’t fully reflect the true state of the channel, thus the strategy could not meet the design standard.This thesis based on the technologies used in transmission mode and combined with analysis of factors which make influence in the transmission mode1/2/3made a research on the improving of inner transmission mode switching technology. Through the analysis about the data getting from simulation and testing, it put forward a new kind of algorithm to improve the date transmitting rate in rapid changes channel state at the area near the edge in the cell. The main content includes: 1. It built a LTE downlink simulation platform based on MATLAB, and then get the simulation data of block error rate and throughput in the flat Rayleigh and PedB channels, in order to analyses the performance of different transmission modes in LTE communication system. Through the analysis of the performance of three kinds of transmission modes without using inner transmission switching strategy, it clearly points out the necessity and advantages of the introduction of inner-transmission mode switching.2. To reflect the actual performance of the three kinds of transmission modes in channel, we set up a test environment which deployed a LTE system with two-cells, and select an appropriate data collection route according in the test environment based on the distribution of the RSRP. This data is processed by programming Perl and MATLAB code. Then an analysis of the performance of transmission modes with the existing inner-transmission mode switching strategy can be made.3. Combined with the simulation results, we propose the algorithm based on that consist of delay, frequency spectral efficiency and the rank which the terminal feedback. Through testing, the algorithm can significantly reduce the frequency of inner-transmission mode switching in rapid changes channel state in transmission mode3. As a result, the overhead of time-frequency resource is reduced; in contrast, it promotes the data transmitting rate of terminal at the area near cell edge by the algorithm.